Regensburg 2007 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 1: Internal Symposium: Physics of fracture

DY 1.5: Vortrag

Montag, 26. März 2007, 11:30–11:45, H2

Continuum theory of fracture — •Denis Pilipenko, Robert Spatschek, and Efim Brener — Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich

A macroscopic theory of fracture in the spirit of nonequilibrium growth processes in pattern formation is discussed. It is commonly believed that crack growth is dictated by microscopic details in the vicinity of the tip. Nevertheless, our continuum theory predicts many important features of fracture. The model is based only on the dynamical theory of elasticity, surface energy and elastically induced phase transitions between a hard and soft solid phase, which corresponds to a nonconserved order parameter. A sharp interface model of crack propagation based on a multipole expansion technique to solve this problem numerically is presented. Here we extend our model to crack growth with a conserved order parameter which is driven by surface diffusion. We obtain steady state solutions with a self-consistently selected propagation velocity and shape of the crack, provided that elastodynamic effects are taken into account. Also, we find a saturation of the steady state crack velocity below the Rayleigh speed, tip blunting with increasing driving force and a tip splitting instability above a critical driving force.